WASHINGTON — Faced with the worst-ever single attack by foreigners on American soil, the U.S. military set up a human intelligence laboratory at Guantanamo that used interrogation and detention practices that they largely made up as they went along.

The world may have thought the U.S. was detaining a band of international terrorists whose questioning would help the hunt for Osama Bin Laden or foil the next 9/11.

But a collection of secret Bush-era intelligence documents not meant to surface for another 20 years shows that the military's efforts at Guantanamo often were much less effective than the government has acknowledged.

Viewed as a whole, the secret intelligence summaries help explain why in May 2009 President Barack Obama, after ordering his own review of wartime intelligence, called America's experiment at Guantanamo "quite simply a mess."

The documents, more than 750 individual assessments of former and current Guantanamo detainees, show an intelligence operation that was tremendously dependant on informants — both prison camp snitches repeating what they'd heard from fellow captives and self-described, at times self-aggrandizing, alleged al Qaida insiders turned government witnesses who Pentagon records show have since been released.

Intelligence analysts are at odds with each other over which informants to trust, at times drawing inferences from prisoners' exercise habits. They order DNA tests, tether Taliban suspects to polygraphs, string together tidbits in ways that seemed to defy common sense.

Guantanamo analysts at times questioned the reliability of some information gleaned from other detainees' interrogations.

Allegations and information from one Yemeni, no longer at Guantanamo, appears in at least 135 detainees' files, prompting Navy Rear Adm. Dave Thomas, the prison camps commander in August 2008, to include this warning:

"Any information provided should be adequately verified through other sources before being utilized."

The same report goes on to praise the captive as an "invaluable intelligence source" for information about al Qaida and Taliban training, operations, personnel and facilities," and warns that he'd be at risk of retaliation if he were released into Yemeni society. He was resettled in Europe by the Obama administration.

In fact, information from just eight men showed up in forms for at least 235 Guantanamo detainees — some 30 percent of those known to have been held there.

In many cases, the detainees made direct allegations of others' involvement in militant activities; in others, they gave contextual information used to help build the edges of a case.

While many other intelligence sources were referred to in those detainee assessment forms, including in some cases confessions by the detainees themselves, the inclusion of information from such a highly questionable group of men would seem to raise serious issues about a key piece of the "mosaic" process at Guantanamo and the decisions that followed.

The documents also show that in the earliest years of the prison camps operation, the Pentagon permitted Chinese and Russian interrogators into the camps — information from those sessions are included in some captives' assessments — something American defense lawyers working free-of-charge for the foreign prisoners have alleged and protested for years.

There's not a whiff in the documents that any of the work is leading the U.S. closer to capturing Bin Laden. In fact, the documents suggest a sort of mission creep beyond the post-9/11 goal of hunting down the al Qaida inner circle and sleeper cells.

The file of one captive, now living in Ireland, shows he was sent to Guantanamo so that U.S. military intelligence could gather information on the secret service of Uzbekistan. A man from Bahrain is shipped to Guantanamo in June 2002, in part, for interrogation on "personalities in the Bahraini court."

That same month, U.S. troops in Bagram airlifted to Guantanamo a 30-something sharecropper whom Pakistani security forces scooped up along the Afghan border as he returned home from his uncle's funeral.

The idea was that, once at Guantanamo, 8,000 miles from his home, he might be able to tell interrogators about covert travel routes through the Afghan-Pakistan mountain region. Seven months later, the Guantanamo intelligence analysts concluded that he wasn't a risk to anyone — and had no worthwhile information. Pentagon records show they shipped him home in March 2003, after more than two years in either American or Pakistani custody.

McClatchy Newspapers obtained the documents last month from WikiLeaks on an embargoed basis to give reporters from seven news organizations — including McClatchy, The Washington Post, the Spanish newspaper El Pais, and the German magazine Der Spiegel — time to catalogue, evaluate and report on them. WikiLeaks abruptly lifted the embargo Sunday night, after the organization became aware that the documents had been leaked to other news organizations, which were about to publish stories about them.

Marked "SECRET // NOFORN," the documents consist of more than 750 intelligence summaries, each consisting on average of between 2 to 12 pages, of the more than 500 detainees who've been transferred from the prison and for the 172 who still remain there. The summaries were written between 2002 and 2008. Many include photographs of the men, information about each man's physical and mental health as well as recommendations on whether to keep them in U.S. custody, hand them over to a foreign government for imprisonment, or set them free.

They make little mention of the abuse and torture scandals that surrounded intelligence gathering — both at secret CIA detention centers abroad and at the Guantanamo camps.

Of an Australian man who came to Guantanamo in May 2002, Army Brig. Gen. Jay Hood noted two years later that the captive confessed while "under extreme duress" and "in the custody of the Egyptian government" to training six of the 9/11 hijackers in martial arts. He had denied the ties by August 2004 and was repatriated five months later.

The documents make clear that intelligence agents elsewhere showed photos of Guantanamo prisoners to prized war-on-terror catches held at secret so-called CIA black-sites, out of reach of the International Red Cross. Notably the reports reflect that at times some captives faces were familiar to Abu Zubayda — whom the CIA waterboarded scores of times.

At times the efforts seem comedic. Guards plucked off ships at sea to walk the cellblocks note who has hoarded food as contraband, who makes noise during the Star Spangled Banner, who sings creepy songs like "La, La, La, La Taliban" and who is re-enacting the 9/11 attacks with origami art.

But they also hint at frightening plots.

If you believe the intelligence profiles, the alleged Sept. 11 mastermind Khalid Sheik Mohammed schooled four men now at Guantanamo in the summer before 9/11 in English and American style-behavior for an ancillary 9/11 attack — on U.S. military sites in Asia.

The documents also show military intelligence offering what appears to be little more than prurient gossip about the detainees.

Saudi Abd al Rahim al Nashiri, 45, who made headlines just week as the first Obama administration candidate for a death penalty tribunal at Guantanamo, is cast in his risk assessment as a high-risk captive. The assessment makes no mention of that the CIA waterboarded him in a secret black-site interrogation before his transfer to military custody but includes his supposed strategy to not be distracted by women:

"Detainee is so dedicated to jihad that he reportedly received injections to promote impotence," an analyst writes, without explanation of the source.

Elsewhere in the files, U.S. military intelligence analysts discussing the dangerousness of two Iraqi men captured in Mazar-e-Sharif, Afghanistan, include this observation: One Iraqi boasted that he had an affair with the other Iraqi's wife, in the husband's house. Both have since been repatriated to Iraq.

And they show how they got it wrong right from the very start. On Day One, the camps commander declared the first airlift of 20 men "the worst of the worst," handpicked hardened terrorists plucked from the battlefield and shown shackled on their knees to their world in mute, blinded submission.

Not so, according to the military's own analysis, which has so far set free eight of the first 20 men — the first of that batch just nine months later as a nobody swept up in the war on terror.

They also show the arc of American understanding of the men who were first locked up at the crude prison camp called X-Ray. Early on in the enterprise, the U.S. military at Guantanamo profiled "The Dirty 30" _that number of men captured along the Afghan-Pakistan border near Parachinar — as Bin Laden bodyguards who had traveled in a pack from Tora Bora to escape the American forces.

But by the time Bush left office, his interagency process had freed 10 of the men. Mostt were sent to Saudi Arabia, some after concluding they were probably not part of the al Qaeda founder's security detail.

Among those men is a convicted war criminal — Guantanamo's lone lifer, Ali Hamza al Bahlul of Yemen — convicted not as a "Dirty 30," but for serving as Bin Laden's media secretary and an al Qaida filmmaker who fed the terror group's propaganda machine.